Argatroban is a generic name assigned to (2R, 4R)-4-methyl-1-[N.sup.2 -((RS)-3-methyl-1,2,3,4-tetrahydro-8-quinolinesulfonyl)-L-arginyl]-2-piper idinecarboxylic acid hydrate represented by the formula: ##STR1## This compound belongs to N.sup.2 -arylsulfonyl-L-arginineamides.
As is disclosed in Japanese Patent Application 88786/1979, argatroban is a selective anti-thrombin substance having entirely new action mechanism which has never been observed in hitherto known medicines. The action mechanism of argatroban includes the selective inhibition of thrombin caused by steric binding of the tripod structure of argatroban to the active site of thrombin. Argatroban strongly inhibits three major actions of thrombin, i.e., (1) fibrin formation, (2) stabilization of fibrin by activation of Factor VIII, and (3) platelet aggregation. As a result, argatroban is clinically known to be applicable in treating limbs ulcer in chronic arterial obstruction and pain at rest, and improving frigidity.
The present inventors completed this invention as explained hereunder in detail by searching for applications of argatroban other than in chronic arterial obstruction in the light of the above unique action mechanism of argatroban.
After intraocular surgery such as retinal and vitreous surgery, cataract operation, and glaucoma operation, post operative fibrin formation in the anterior chamber is often observed. This is a very important problem since the fibrin formation must be prevented for establishing satisfactory post operative management. For example, the fibrin formation after intraocular lens implantation results in not only poor visual prognosis, but also possible development of serious condition, such as complication of glaucoma. The fibrin formation after vitreous surgery also interferes with the post operative fundus examination to disturb the appropriate treatment or management of vitreo-retinal disease. Further, the fibrin formation can cause intractable anterior proliferative vitreo-retinal condition.
On the background as explained above, it has been recognized that prevention of postoperative fibrin formation is very important, but is measure to cope with it has been reported to date.